Similar to that demonstrated in elderly subjects, cytokine profiles of HIV+ individuals have been shown to be dominated by elevated production of IL-2, IL-17, IL-6 and TNFα following influenza vaccination and are correlated with poor antibody titres [90, 107] as well as low frequencies of resting memory B cells, IL-21-producing Tfh cells and ASCs [92]. Here, IL21 is linked to influenza.